A Min–Max Property of Chordal Bipartite Graphs with Applications
We show that if G is a bipartite graph with no induced cycles on exactly 6 vertices, then the minimum number of chain subgraphs of G needed to cover E ( G ) equals the chromatic number of the complement of the square of line graph of G . Using this, we establish that for a chordal bipartite graph G...
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Published in | Graphs and combinatorics Vol. 26; no. 3; pp. 301 - 313 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
Japan
Springer Japan
01.05.2010
Springer Nature B.V |
Subjects | |
Online Access | Get full text |
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Summary: | We show that if
G
is a bipartite graph with no induced cycles on exactly 6 vertices, then the minimum number of chain subgraphs of
G
needed to cover
E
(
G
) equals the chromatic number of the complement of the square of line graph of
G
. Using this, we establish that for a chordal bipartite graph
G
, the minimum number of chain subgraphs of
G
needed to cover
E
(
G
) equals the size of a largest induced matching in
G
, and also that a minimum chain subgraph cover can be computed in polynomial time. The problems of computing a minimum chain cover and a largest induced matching are NP-hard for general bipartite graphs. Finally, we show that our results can be used to efficiently compute a minimum chain subgraph cover when the input is an interval bigraph. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 0911-0119 1435-5914 |
DOI: | 10.1007/s00373-010-0922-0 |